This invention relates to a reversing apparatus for motor-actuated devices for detecting a predetermined abnormal load on such devices and for stopping and reversing the drive motor in response to the presence of such abnormal load, such as the presence of an obstruction. The reversing apparatus is especially applicable to powered sliding door operating systems for vehicles and, more particularly, to such powered sliding door operating systems for van type vehicles having a door opening in a side wall of the van. In such applications of the invention, the sliding door is moved generally parallel to the van side wall during its initial closing movement and for a major portion of its full closing movement as well as during a major portion of its full opening movement, including its final opening movement. Typically, the sliding door moves generally toward and generally away from the plane of the door opening during a portion of its respective final closing and initial opening movements, so as to be flush with the side wall when fully closed, and so as to be alongside of, and parallel to, the side wall, generally rear of the door opening, when fully opened.
In sliding door systems of the type mentioned above, upper and lower forward guide rails are attached to the top and bottom portions, respectively, of the door opening, and a rear guide rail is attached to the exterior of the side wall, at an elevation approximately midway between the elevation of the upper and lower forward guide rails. The respective forward end portions of the various guide rails are curved inwardly of the body of the van, and bracket and roller assemblies are fastened to the respective upper and lower forward ends of the sliding door, as well as to an intermediate position at the rear end of the sliding door. Such bracket and roller assemblies are slidingly supported in the guide rails to guide the door through its opening and closing movements.
Various portions of the opening and closing movements of van sliding doors have different power requirements. Thus, the initial door closing movement and a major portion of the subsequent door closing movement are high displacement/low force translational movements, during which little force is required to achieve large door movements since only frictional resistance and grade-caused gravity resistances must be overcome. Similarly, the final opening movement and a major portion of the preceding opening movement are also high displacement/low force translational movements for the same reasons. In contrast however, a portion of the final closing movement of the door is a low displacement/high force movement. This is because during final closing, an elastomeric weather seal surrounding the door opening must be compressed, and an unlatched latch bolt on the door must engage and be rotated to a latched position by a striker pin at the rear of the van body door opening. During manual operation, sliding van doors are typically moved with great momentum through their entire closing movements in order to assure full weather strip compression and latch bolt operation at the end of such movement.
Various powered van door systems have been developed in the past, including those described in the above-mentioned related U.S. patents. Another such system is illustrated in U.S. Pat. No. 4,612,729, issued to Sato. In the Sato patent, a motor driven pinion carried by the lower front bracket and roller assembly of the door cooperates with a rack gear carried by the lower front guide rail in the door opening to move the door between its fully open and fully closed positions. In this arrangement, as in the case of the manual door operation discussed above, a high momentum is still required during the entire closing movement.
Similarly, U.S. Pat. No. 4,617,757, issued to Kagiyama et al, and U.S. Pat. No 4,640,050, issued to Yamagishi et al also represents additional examples of powered van door systems. The systems employ cable drives coupled to the lower front bracket and roller assemblies of the doors for opening and closing movements However, these systems also rely on high momentum during the entire closing movement.
U.S. Pat. No. 4,462,185 issued to Shibuki et al describes still another powered van door system. In this system, a friction wheel engages the bottom portion of the door and drives the door through the major portions of its opening and closing movements parallel to the side wall of the van. Turntable arms are pivotably connected end-to-end between the friction wheel and the floor of the door opening and draws the rear of the door inwardly to compress the weather strip, While this prior art design appears to operate with lower momentum forces during closing movement than those discussed above, it requires a complicated, costly mechanism that is difficult to install and difficult to repair in the event of a breakdown. Moreover, retrofiting this mechanism to a vehicle not originally equipped with a powered door system would be inordinately difficult.
In addition to the foregoing prior art systems, final closing devices or clamping mechanisms for powering the final, low-displacement/high-force movement of sliding van doors have been developed by the assignee of the present invention and are described in the above-mentioned U.S. Pat. Nos. 4,775,178 and 4,842,313, the disclosures of which are incorporated by reference herein. In each of these systems, the door includes a latch bolt member moveable between latched and unlatched positions, as well as a handle or a lock member movable between open and closed positions. The final closing device or clamping mechanisms each includes a striker support plate mounted on the vehicle body at the rear of the door opening for rotational movement about a perpendicular axis, a striker pin projecting from the striker support plate at a position offset from the axis, and means carried by the vehicle body for rotating the striker support plate. The striker pin is movable between extended and retracted positions so that when the striker pin is engaged by the latch member bolt the striker support plate is rotated, and the sliding door is moved between a partially open position away from the door opening and a fully closed position. In addition to disclosing the foregoing structure, U.S. Pat. No 4,842,313 also discloses a crashworthiness feature that adds a pawl and ratchet mechanism to prevent the striker support plate from being reversely rotated in response to high door opening forces from the inside of the vehicle.
Although U.S. Pat. Nos. 4,775,178 and 4,842,313 illustrate excellent final closing systems for sliding van doors, they do not include provisions for powering van doors through the major portions of opening and closing movements, nor do they include provisions for powering van doors during late closing movements to the point where the latch bolt mechanisms engage with, and close about, the striker pins of the clamping mechanisms.
Improved powered sliding door operator systems for van type vehicles are disclosed in the above-mentioned U.S. Pat. No. 4,862,640, with the disclosed systems having provisions (i) for powering sliding van doors through the major portions of opening and closing movements, (ii) for powering sliding van doors during late closing movements to engage the latch bolt mechanisms with the striker pins, and (iii) for finally clamping sliding van doors to a fully closed position. In such patent the disclosure of which is hereby incorporated by reference, the door is supported adjacent its forward end by forward brackets slidable in upper and lower forward guide members carried by the vehicle body, and is supported adjacent its rear end by a rear bracket slidable in a mid-level rear guide member carried on the outside of the vehicle side panel. Motor driven cable members are attached to the rear bracket and supported adjacent opposite ends of the rear guide member and are employed to move the door through its opening movement through its initial closing movement, and through an initial portion of its final closing movement. The final portion of its closing movement is accomplished using a final clamping mechanism of the type disclosed in the above-mentioned U.S. Pat. No. 4,842,313.
It is therefore, a primary object of the present invention to provide an improved powered sliding door operator system for van type vehicles in which the sliding door is moved with low momentum between its fully open position and its nearly closed position, and which completely closes the sliding door in a slow controlled manner.
Another object of this invention is to provide an improved powered sliding door operator system in which the manual effort required to open and close the sliding door is substantially reduced, in which near-normal manual operation of the sliding door is preserved in the event of a failure of the powered system, and in which the powered system can be actuated from either the vehicle driver's seat or the door itself.
A primary object of the present invention is to provide a mechanism or system capable of detecting an obstruction encountered by a moving door, or other moving member in other powered actuating devices, such as powered vehicle windows, for example, and then stopping and/or reversing such motion in order to prevent damage to the obstruction, to the moving door or other member, or to the powered actuating equipment.
Still another related object of the invention is to accomplish the above-mentioned obstruction detection and motion reversing within a predetermined, acceptable time, within a predetermined obstruction resistance force when the moving door or member is disposed within a predetermined range of angular positions (such as those resulting from a vehicle situated on an upwardly or downwardly inclined grade), and within a predetermined temperature range likely to be encountered by the powered vehicle door system or other powered actuating system.
In accordance with one exemplary embodiment or application of the invention, a powered door operator system is provided for a door slidingly supported relative to a door opening in a side panel of a vehicle body. The door is supported adjacent its forward end by at least one forward bracket that is slidable in a forward guide member and adjacent its rear end by a rear bracket that is slidable in a rear guide member. The guide members guide the door (i) through an initial closing movement generally parallel to the side panel (ii) through a final opening movement generally parallel to the side panel, (iii) through at least a portion of its final closing movement generally toward the plane of the door opening, and (iv) through at least a portion of its initial opening movement generally away from the plane of the door opening. The door operator system includes cable members coupled to the forward and rear ends of the door for driving the door along the guide members to thereby move the door through its initial and final opening and closing movements, substantially without the need for cable spool assembly tensioning mechanisms.
An improved cable spool arrangement is provided in such exemplary application of the invention for a cable-actuated device, such as for a powered van door system, for example, having a drive mechanism for selectively rotating the cable spool about an axis in either direction and one or more cables each having one end interconnected with a movable member, such as a sliding door. The cable spool includes a cable attachment arrangement for securing the opposite end or ends of the cable or cables to the cable spool. A groove, slot, or other open channel-like opening is formed along a generally helical path on a circumferential portion of the cable spool. The groove is adapted for windingly receiving or taking up at least one of the cables therein as the cable spool is rotated in one direction, and for unwindingly releasing or paying out at least one of the cables therefrom as the cable spool is rotated in the opposite direction. The helical configuration of the cable spool groove eliminates the undesirable constantly changing effective spool radius that results from cable wrap-up or stacking on cable spools having one or more circular or non-helical grooves. Thus, the cable take-up and pay-out rates relative to cable spool rotation, can be more closely defined and controlled.
In addition, in the preferred cable spool in such exemplary application, the radial depth (and thus the wrap-up and pay-out radius) of the helical groove varies along at least a portion of the helical path in order to cause at least one of the cables to be wound onto, and paid out from, the varying-depth portion of the helical groove at a correspondingly varying rate with respect to cable spool rotation. This effect can be used to cause movement of at least a portion of the sliding door, or other such movable member, at a correspondingly varying rate with respect to cable spool rotation. If desired in a given application, the cable spool can have a generally constant radial depth of the helical groove along second portion of the helical path in order to cause at least one of the cables to be wound onto, and paid out from, the constant-depth portion of the helical groove at a generally constant rate with respect to cable spool rotation. This effect can be used to cause movement of at least a portion of the sliding door or other movable member, at a generally constant rate with respect to cable spool rotation.
In accordance with the present invention, a reversing apparatus is provided for detecting the presence of an obstruction encountered by the movable door, or other movable member such as a power window, for example, and causing a stoppage and/or reversal of its motion in order to substantially prevent damage to the obstruction, the door or other movable member, or the powered actuating system. The reversal apparatus uses changes in drive motor currents during door actuation that indicate the presence of an obstruction by comparing the instantaneous motor current with a reference current that is averaged over a predetermined short time interval This feature makes the reversing apparatus independent of the normally varying drive motor current, with such normal variance resulting from the changes in the types of door closing movements described above. Thus, the reversing apparatus properly senses or detects the presence of an obstruction even for van-type sliding doors or other movable powered-actuated members, that undergo varying or complex movements, or changing relationships between travel speed and force at various stages of their operation, and that draw different amounts of drive motor current when disposed in different angular, or grade-caused, orientations.
Additional objects, advantages, and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.